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Theorem tfinds 4666
Description: Principle of Transfinite Induction (inference schema), using implicit substitutions. The first four hypotheses establish the substitutions we need. The last three are the basis, the induction hypothesis for successors, and the induction hypothesis for limit ordinals. Theorem Schema 4 of [Suppes] p. 197. (Contributed by NM, 16-Apr-1995.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)
Hypotheses
Ref Expression
tfinds.1  |-  ( x  =  (/)  ->  ( ph  <->  ps ) )
tfinds.2  |-  ( x  =  y  ->  ( ph 
<->  ch ) )
tfinds.3  |-  ( x  =  suc  y  -> 
( ph  <->  th ) )
tfinds.4  |-  ( x  =  A  ->  ( ph 
<->  ta ) )
tfinds.5  |-  ps
tfinds.6  |-  ( y  e.  On  ->  ( ch  ->  th ) )
tfinds.7  |-  ( Lim  x  ->  ( A. y  e.  x  ch  ->  ph ) )
Assertion
Ref Expression
tfinds  |-  ( A  e.  On  ->  ta )
Distinct variable groups:    x, y    x, A    ch, x    ta, x    ph, y
Allowed substitution hints:    ph( x)    ps( x, y)    ch( y)    th( x, y)    ta( y)    A( y)

Proof of Theorem tfinds
Dummy variable  z is distinct from all other variables.
StepHypRef Expression
1 tfinds.2 . 2  |-  ( x  =  y  ->  ( ph 
<->  ch ) )
2 tfinds.4 . 2  |-  ( x  =  A  ->  ( ph 
<->  ta ) )
3 dflim3 4654 . . . . 5  |-  ( Lim  x  <->  ( Ord  x  /\  -.  ( x  =  (/)  \/  E. y  e.  On  x  =  suc  y ) ) )
43notbii 287 . . . 4  |-  ( -. 
Lim  x  <->  -.  ( Ord  x  /\  -.  (
x  =  (/)  \/  E. y  e.  On  x  =  suc  y ) ) )
5 iman 413 . . . . 5  |-  ( ( Ord  x  ->  (
x  =  (/)  \/  E. y  e.  On  x  =  suc  y ) )  <->  -.  ( Ord  x  /\  -.  ( x  =  (/)  \/ 
E. y  e.  On  x  =  suc  y ) ) )
6 eloni 4418 . . . . . . 7  |-  ( x  e.  On  ->  Ord  x )
7 pm2.27 35 . . . . . . 7  |-  ( Ord  x  ->  ( ( Ord  x  ->  ( x  =  (/)  \/  E. y  e.  On  x  =  suc  y ) )  -> 
( x  =  (/)  \/ 
E. y  e.  On  x  =  suc  y ) ) )
86, 7syl 15 . . . . . 6  |-  ( x  e.  On  ->  (
( Ord  x  ->  ( x  =  (/)  \/  E. y  e.  On  x  =  suc  y ) )  ->  ( x  =  (/)  \/  E. y  e.  On  x  =  suc  y ) ) )
9 tfinds.5 . . . . . . . . 9  |-  ps
10 tfinds.1 . . . . . . . . 9  |-  ( x  =  (/)  ->  ( ph  <->  ps ) )
119, 10mpbiri 224 . . . . . . . 8  |-  ( x  =  (/)  ->  ph )
1211a1d 22 . . . . . . 7  |-  ( x  =  (/)  ->  ( A. y  e.  x  ch  ->  ph ) )
13 nfra1 2606 . . . . . . . . 9  |-  F/ y A. y  e.  x  ch
14 nfv 1609 . . . . . . . . 9  |-  F/ y
ph
1513, 14nfim 1781 . . . . . . . 8  |-  F/ y ( A. y  e.  x  ch  ->  ph )
16 vex 2804 . . . . . . . . . . . . 13  |-  y  e. 
_V
1716sucid 4487 . . . . . . . . . . . 12  |-  y  e. 
suc  y
181rspcv 2893 . . . . . . . . . . . 12  |-  ( y  e.  suc  y  -> 
( A. x  e. 
suc  y ph  ->  ch ) )
1917, 18ax-mp 8 . . . . . . . . . . 11  |-  ( A. x  e.  suc  y ph  ->  ch )
20 tfinds.6 . . . . . . . . . . 11  |-  ( y  e.  On  ->  ( ch  ->  th ) )
2119, 20syl5 28 . . . . . . . . . 10  |-  ( y  e.  On  ->  ( A. x  e.  suc  y ph  ->  th )
)
22 raleq 2749 . . . . . . . . . . . 12  |-  ( x  =  suc  y  -> 
( A. z  e.  x  [ z  /  x ] ph  <->  A. z  e.  suc  y [ z  /  x ] ph ) )
23 nfv 1609 . . . . . . . . . . . . . . 15  |-  F/ x ch
2423, 1sbie 1991 . . . . . . . . . . . . . 14  |-  ( [ y  /  x ] ph 
<->  ch )
25 sbequ 2013 . . . . . . . . . . . . . 14  |-  ( y  =  z  ->  ( [ y  /  x ] ph  <->  [ z  /  x ] ph ) )
2624, 25syl5bbr 250 . . . . . . . . . . . . 13  |-  ( y  =  z  ->  ( ch 
<->  [ z  /  x ] ph ) )
2726cbvralv 2777 . . . . . . . . . . . 12  |-  ( A. y  e.  x  ch  <->  A. z  e.  x  [
z  /  x ] ph )
28 cbvralsv 2788 . . . . . . . . . . . 12  |-  ( A. x  e.  suc  y ph  <->  A. z  e.  suc  y [ z  /  x ] ph )
2922, 27, 283bitr4g 279 . . . . . . . . . . 11  |-  ( x  =  suc  y  -> 
( A. y  e.  x  ch  <->  A. x  e.  suc  y ph )
)
3029imbi1d 308 . . . . . . . . . 10  |-  ( x  =  suc  y  -> 
( ( A. y  e.  x  ch  ->  th )  <->  ( A. x  e.  suc  y ph  ->  th ) ) )
3121, 30syl5ibrcom 213 . . . . . . . . 9  |-  ( y  e.  On  ->  (
x  =  suc  y  ->  ( A. y  e.  x  ch  ->  th )
) )
32 tfinds.3 . . . . . . . . . . 11  |-  ( x  =  suc  y  -> 
( ph  <->  th ) )
3332biimprd 214 . . . . . . . . . 10  |-  ( x  =  suc  y  -> 
( th  ->  ph )
)
3433a1i 10 . . . . . . . . 9  |-  ( y  e.  On  ->  (
x  =  suc  y  ->  ( th  ->  ph )
) )
3531, 34syldd 61 . . . . . . . 8  |-  ( y  e.  On  ->  (
x  =  suc  y  ->  ( A. y  e.  x  ch  ->  ph )
) )
3615, 35rexlimi 2673 . . . . . . 7  |-  ( E. y  e.  On  x  =  suc  y  ->  ( A. y  e.  x  ch  ->  ph ) )
3712, 36jaoi 368 . . . . . 6  |-  ( ( x  =  (/)  \/  E. y  e.  On  x  =  suc  y )  -> 
( A. y  e.  x  ch  ->  ph )
)
388, 37syl6 29 . . . . 5  |-  ( x  e.  On  ->  (
( Ord  x  ->  ( x  =  (/)  \/  E. y  e.  On  x  =  suc  y ) )  ->  ( A. y  e.  x  ch  ->  ph ) ) )
395, 38syl5bir 209 . . . 4  |-  ( x  e.  On  ->  ( -.  ( Ord  x  /\  -.  ( x  =  (/)  \/ 
E. y  e.  On  x  =  suc  y ) )  ->  ( A. y  e.  x  ch  ->  ph ) ) )
404, 39syl5bi 208 . . 3  |-  ( x  e.  On  ->  ( -.  Lim  x  ->  ( A. y  e.  x  ch  ->  ph ) ) )
41 tfinds.7 . . 3  |-  ( Lim  x  ->  ( A. y  e.  x  ch  ->  ph ) )
4240, 41pm2.61d2 152 . 2  |-  ( x  e.  On  ->  ( A. y  e.  x  ch  ->  ph ) )
431, 2, 42tfis3 4664 1  |-  ( A  e.  On  ->  ta )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    <-> wb 176    \/ wo 357    /\ wa 358    = wceq 1632   [wsb 1638    e. wcel 1696   A.wral 2556   E.wrex 2557   (/)c0 3468   Ord word 4407   Oncon0 4408   Lim wlim 4409   suc csuc 4410
This theorem is referenced by:  tfindsg  4667  tfindes  4669  tfinds3  4671  oa0r  6553  om0r  6554  om1r  6557  oe1m  6559  oeoalem  6610  r1sdom  7462  r1tr  7464  alephon  7712  alephcard  7713  alephordi  7717  rdgprc  24222  tartarmap  25991
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1536  ax-5 1547  ax-17 1606  ax-9 1644  ax-8 1661  ax-13 1698  ax-14 1700  ax-6 1715  ax-7 1720  ax-11 1727  ax-12 1878  ax-ext 2277  ax-sep 4157  ax-nul 4165  ax-pr 4230  ax-un 4528
This theorem depends on definitions:  df-bi 177  df-or 359  df-an 360  df-3or 935  df-3an 936  df-tru 1310  df-ex 1532  df-nf 1535  df-sb 1639  df-eu 2160  df-mo 2161  df-clab 2283  df-cleq 2289  df-clel 2292  df-nfc 2421  df-ne 2461  df-ral 2561  df-rex 2562  df-rab 2565  df-v 2803  df-sbc 3005  df-dif 3168  df-un 3170  df-in 3172  df-ss 3179  df-pss 3181  df-nul 3469  df-if 3579  df-pw 3640  df-sn 3659  df-pr 3660  df-tp 3661  df-op 3662  df-uni 3844  df-br 4040  df-opab 4094  df-tr 4130  df-eprel 4321  df-po 4330  df-so 4331  df-fr 4368  df-we 4370  df-ord 4411  df-on 4412  df-lim 4413  df-suc 4414
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